The myoepi cells lining the ducts are spindleshaped cells,oriented parallel to the long axis of ducts as a continuous layer. Vimentin as a marker of myoepithelial cells in salivary gland. It is assumed that they take part in the expulsion of the saliva, and possibly they support. Myoepithelial tumours of the salivary glands current. Epithelialmyoepithelial carcinomas comprise approximately 1 % of all salivary gland neoplasms. Although myoepithelial cells are a component of several salivary gland neoplasms388 table. Myoepithelial cells normally surround ducts in secretory organs, such as the breasts, salivary glands, and cutaneous sweat glands. Myoepithelial carcinoma of salivary gland is a malignant epithelial tumor, composed almost only of myoepithelial cell type, affecting either the major or minor salivary glands. Fineneedle aspiration of epithelialmyoepithelial carcinoma. Myoepithelial cells are a normal constituent of the salivary acini and smaller ducts, and are found between the epithelial cells and the basement membrane. R26 tdtomato mice, persistent and heritable tdtomato.
The cystic lesion has a mildly fibrotic appearing wall, is lined by histiocytes intermixed with rare lymphocytes, and contains mucous and macrophages. Myoepithelial carcinoma an overview sciencedirect topics. Primary pulmonary myoepithelial carcinoma interactive. To describe the clinical and cytopathologic findings in 15 cases of salivary gland myoepithelial neoplasms and to assess. Invasive myoepithelial carcinoma ex pleomorphic adenoma of. Thirteen men and 12 women aged 24 to 77 years mean age, 55 yrs participated in the study, and most presented with a painless mass. They are interposed between the secretory cells and the basal lamina. Pathophysiology of myoepithelial cells in salivary glands ncbi.
Myoepithelial carcinoma mec is a rare salivary gland tumor, accounting for 0. Around acini, myoepithelial cells have a stellate, multiprocessed morphology in three. Therefore, accumulation of these rare cases is important. Epithelialmyoepithelial carcinoma of salivary glands. Jul 10, 2015 myoepithelial cells mecs are found in multiple glandular organs such as the lacrimal, salivary, harderian, sweat, prostate, and mammary glands. Its designation stresses the cellular com position of the neoplasm, as a carcinoma made by duct epithelial cells and myoepithelial cells corio et al. Outer tubular cells of organoid doublelayered tubular structures seen in pleomorphic and monomorphic adenoma and adenoid cystic carcinoma, and cystlining. Myoepithelial cell, neoplasm, salivary gland tumor. Current perspectives in salivary gland tumors c pramod redder 1, v suresh kandagal 1, nupura vibhute 1, pramod s ingaleshwar 2, sharan j shetty 2, sameer ahamad 3 1 department of oral pathology and microbiology, school of dental sciences, krishna institute of medical sciences university, karad, maharashtra, india 2 department of oral pathology and microbiology, a. In salivary glands, the myoepithelial cells that surround the intercalated ducts are spindled in contrast to the large stellate ones that envelop the acini. Generation of functional salivary gland tissue from human.
Secretions from glands are expelled by the contractile function of myoepithelial cells. Epithelial myoepithelial carcinoma emc is a rare salivary gland malignancy comprising less than 1% of all salivary gland neoplasms. Myoepithelial carcinoma of the retromolar area in a young female. To date, no definitive therapeutic approach can compensate the impairment of salivary glands, and treatment are purely symptomatic. In salivary glands and other exocrine glands, there are starshaped cells lying. They can be recognized with various immunohistochemical markers, although none is specific or reliable in every case. Myoepithelial cells do not have a demonstrable secretory capability, but they can store glycogen in abundance. The myoepithelial cell at a glance myoepi cells are attached to the basement memb by hemidesmosomes adjacent luminal epithelial cells by desmosomes. Mar 20, 2020 organ replacement regenerative therapy based on human adult stem cells may be effective for salivary gland hypofunction.
A variety of diseases, such as cancer, autoimmune diseases, infections and physical traumas, can alter the functionality of these glands, greatly impacting the quality of life of patients. The sections show a stratified squamous epithelium with a thin layer of parakeratosis, minor salivary glands, and a wellcircumscribed cystic lesion. Four cases of epithelial myoepithelial carcinoma of the salivary glands arose as painless masses in patients over 60 years old, three in the parotid and one in the submandibular gland. Cells demonstrate plasticity following injury, but the extent of this phenomenon and the cellular mechanisms involved remain underexplored. The cells that are found in the connective tissue of the salivary glands are similar to those in other connective tissues of the body and include broblasts, macrophages, mast cells, histology 70. These may be positive for alpha smooth muscle actin and can contract and expel the secretions of exocrine glands. Salivary glands are composed mainly of parenchymal cells acini and myoepithelial cells mecs. These tumors arise from portions of the salivary duct system in which myoepithelial cells are not normally found. Limited regeneration of adult salivary glands after severe. Pdf download for myoepithelial cell markers in salivary gland neoplasms. For most of these, the original diagnosis was malignant mixed tumor. Although some case series exist, the clinical features of mec vary considerably depending on the site of origin.
These glands are divided into numerouslobules which contain the secretory units, which are called acini. Read innervation and myoepithelial arrangements in the submandibular salivary gland of ferret investigated by enzyme, catecholamine and filament histochemistry, archives of oral biology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Various benign and malignant tumors of these structures have occasionally been reported in the lung. Epithelialmyoepithelial carcinoma comprises intercalated ductlike structures with an inner component of epithelial cells, surrounded by an outer component of clear myoepithelial cells. Myoepithelial carcinoma is a rare malignant cancerous tumor that usually occurs in the salivary glands in the mouth, but can also occur in skin and soft tissues. Isolated human submandibular gland stemprogenitor cells hsmgepispcs were. Salivary gland myoepithelial carcinoma mc or malignant myoepithelioma is a rare entity. The samples analyzed included tumors in which the participation of myoepithelial cells as a tumoral component has been postulated, i. Dec 01, 2018 myoepithelial carcinoma of salivary gland is a malignant epithelial tumor, composed almost only of myoepithelial cell type, affecting either the major or minor salivary glands. The common developmental origin of myoepithelial cells with the basal cells of the larger ducts is displayed in the mature glands by shared structural and immunohistochemical features, although most such basal cells do not have the distinguishing features of myoepithelial cells, such as myofibrils. Epithelialmyoepithelial carcinoma of the parotid gland author. These cells structurally resemble epithelial cells and smooth muscles and, thus, are referred to as myoepithelial cells mecs. Diagnostic dilemmas caused are due to inadequacy of characterizing.
These are characterized by high expression of actin and myosin myofilaments in their cytoplasm, which make their contractility one of their main functions. Cd29, s100 and calponin were detected increasingly as salivary gland structure matured and in fully developed salivary gland. Myoepithelial cells surround the acini but have also been found around intercalary and striated ducts. They can be routinely identified in many normal tissues that have secretory functions, such as the major and minor salivary glands, lacrimal glands, sweat glands, breasts, and the prostate. Its longterm prognosis remains unknown because of the paucity of reported cases with longterm followup. Primary clear cell tumors of the salivary glands include epithelialmyoepithelial carcinoma, clear cell carcinoma, and clear cell myoepithelial carcinoma. Jan 29, 20 the myoepithelial cell at a glance myoepi cells are attached to the basement memb by hemidesmosomes adjacent luminal epithelial cells by desmosomes. Physiology, pathology and regeneration of salivary glands. Only 1% of all salivary gland neoplasms are myoepitheliomas. Pathophysiology of myoepithelial cells in salivary glands. However, the generated tissues are immature because the signaling factors that induce the differentiation of human salivary gland stem cells into salivary glands are unknown. They are preponderantly tumors of the parotid glands with a relatively low mortality but a decided lo.
Epithelialmyoepithelial carcinoma of salivary glands john. Oct 28, 2016 myoepithelial carcinoma mec is a rare salivary gland tumor. Salivary glands are essential structures in the oral cavity. Sep 10, 2018 epithelial myoepithelial carcinoma emc of salivary gland is a malignant epithelial tumor, composed of two distinct cell types, affecting either the major or minor salivary glands. Clear cell carcinoma consists exclusively of luminal.
Epithelial myoepithelial carcinomas comprise approximately 1 % of all salivary gland neoplasms. Four cases of epithelialmyoepithelial carcinoma of the salivary glands arose as painless masses in patients over 60 years old, three in the parotid and one in the submandibular gland. Myoepithelial cell markers in salivary gland neoplasms cristiane. Mecs structurally resemble both epithelial cells and smooth muscles. We now need to understand more about their origin and to reconsider their place in the complex process of mammary morphogenesis. Khademi b, kazemi t, bayat a, bahranifard h, daneshbad y, mohammadianpanah m. Vimentin as a marker of myoepithelial cells in salivary. Myoepithelial cells are found in exocrine glands, including highly developed glands, such as the breast, where they form a major population surrounding glandular acini and ducts, and squeeze secretions from the glandular lumina. Mar 01, 2015 myoepithelial cells mec are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary glands. Pdf spindle cell myoepithelioma of the parotid gland. Myoepithelial cell markers in salivary gland neoplasms.
Mammary myoepithelial cells have recently been described as natural tumour suppressors. Myoepithelial cells are believed to be of ectodermal origin. It also consists of branched ducts for the passage of the saliva. The importance of being a myoepithelial cell breast.
It is noteworthy that myoepithelial cells of the salivary glands are located between the basal layer and plasmatic membrane of the secretory acinar cells and interspersed ducts klein, 2002. It is observed in a wide age category of children and adults. Myoepithelioma is usually a benign tumor arising from neoplastic myoepithelial or basket cells which are found between the basement membrane and the basal. Myoepithelial cells are ectodermally derived contractile cells that act as smooth muscle cells. Epithelialmyoepithelial carcinoma of the salivary glands emc is a rare neoplasm first described by don ath et al. Differential ckit expression pattern in major salivary glands. Other than the head and neck, mec has been reported in the lung, breast, bronchus, mediastinum. Myoepithelial cells mecs are considered to be a key participant in most salivary gland diseases, particularly tumors. Sep 21, 2018 ckit is broadly expressed in the major salivary glands of adult mice.
Pdf myoepithelial cells are normal constituent of the salivary acini and smaller ducts, and are found between. These cells surround glandular secretory epithelium. Myoepithelial carcinomas are described as the malignant version of benign myoepitheliomas. Normal and neoplastic myoepithelial cells in salivary glands.
In some tumors of the salivary glands, myoepithelial cells do not participate in histogenesis. Epithelialmyoepithelial carcinoma of salivary gland. Know the localization of myoepithelial cells and nerves in relation to the acinar cells, and their role in secretory functions. The importance of being a myoepithelial cell breast cancer. Epithelialmyoepithelial carcinoma of the parotid gland. Epithelial myoepithelial carcinoma of the salivary glands emc is a rare neoplasm first described by don ath et al. Research article proliferative activity of myoepithelial cells in. To investigate the lineage potential of k5expressing intercalated duct cells, we crossed the krt5 creer mouse, carrying a tamoxifeninducible cre recombinase creer, with the r26 tdtomato reporter strain. These tumors arise from portions of the salivary duct system in. Mc usually presents as a slowgrowing painless mass arising in the parotid gland, but may involve other. Mec generally arises from the parotid gland 2982 % of all cases and rarely from the submandibular gland, minor salivary glands, or the upper respiratory tract 24. In adult salivary glands, k5 expression is restricted to intercalated and basal excretory ducts and myoepithelial cells. The structure and function of myoepithelial cells in. To clarify the discrepancy between ckit immunoreactivity of tissue and single cell suspensions of adult smgs, we used a.
Epithelialmyoepithelial carcinoma emc is a rare salivary gland malignancy comprising less than 1% of all salivary gland neoplasms. The protein p63 was present in all stages of salivary gland morphogenesis from initial bud to terminal bud stage. Neoplastic myoepithelial cells in both benign and malignant tumours can take several forms, including epithelioid, spindle. We compared the immunoexpression of 5 myoepithelial cell mec markers asmoothmuscle actin, calponin, hcaldesmon, vimentin, and s100protein using 16 pleomorphic adenomas pa, 15 adenoid cystic carcinomas acc, and 3 epithelialmyoepithelial carcinomas emc of salivary glands. Myoepithelial cells sometimes referred to as myoepithelium are cells usually found in glandular epithelium as a thin layer above the basement membrane but generally beneath the luminal cells. Salivary glandlike tumors of the breast show a great variety of architectural patterns and cellular differentiations such as glandular, myoepithelial, squamous, and even mesenchymal phenotypes. Primary cutaneous neoplasms of myoepithelial differentiation are uncommon.
Ip045, spindle cell myoepithelioma of the parotid gland. Myoepithelial neoplasms are well recognized in the salivary glands 14,15. K5k14positive cells contribute to salivary glandlike. Mecs play an important role in supporting the morphogenesis, differentiation and polarization of salivary acini. Isolated human submandibular gland stemprogenitor cells hsmgepispcs were characterized and three. Myoepithelial cell an overview sciencedirect topics. Effects of benzodiazepines on acinar and myoepithelial cells. Saliva is a fluid secreted by the salivary glands that keeps the oral cavity moist and also coats the teeth along with mucosa. Apr 23, 2015 in salivary glands and other exocrine glands, there are starshaped cells lying between the basal lamina and the acinar and ductal cells. Histologically, all the tumours were composed of small ducts with a double cell lining surrounded by a basement membrane. The myoepi cells in tdlus discontinuous, stellate shaped and form a. Pdf epithelialmyoepithelial carcinoma of the parotid gland. They envelop the glandular, acinar, and ductal elements of various organs, especially breast and salivary glands.
Histochemical studies of myoepithelial cells were undertaken in order to provide further information about the structure and function of these cells in their normal environment in salivary glands and as an aid in their identification in abnormal situations such as in salivary gland tumours. The histopathology shows several architectural patterns such as trabecular, glandular, partly cystic, and solid. Epithelialmyoepithelial carcinoma emc of salivary gland is a malignant epithelial tumor, composed of two distinct cell types, affecting either the major or minor salivary glands. Immunohistochemistry of myoepithelial cells during development of. They are found in the sweat glands, mammary glands, lacrimal glands, and salivary glands.
Neoplastic myoepithelial cells in both benign and malignant tumours can take several forms, including epithelioid. Myoepithelial cells mec of the salivary glands in health. Myoepithelial cells of salivary glands have a complex. The physiological role of these cells in salivary glands is remarkably little known. The salivary gland possesses tubuloacinar units, and these are merocrine. We compared the immunoexpression of 5 myoepithelial cell mec markers. In salivary glands and other exocrine glands, there are starshaped cells lying between the basal lamina and the acinar and ductal cells. Nov 18, 2016 myoepithelial carcinoma is a rare malignant cancerous tumor that usually occurs in the salivary glands in the mouth, but can also occur in skin and soft tissues. Myoepithelial carcinoma can arise in both minor and major salivary glands but with a predilection for the parotid gland.
Myoepithelial cells mec are found in the secretory units of many mammalian exocrine glands such as mammary, sweat, lacrimal and salivary glands. Epithelialmyoepithelial carcinoma of the salivary glands. Approximately 66% of these tumors occur in a part of the salivary gland, known as the parotid gland. We report a case of cutaneous myoepithelial carcinoma in a 47yearold man with a history of endstage renal disease and renal transplant 19 years prior who presented to the hospital with a 3month history of diffuse bone pain and an ulcerated scalp mass with multiple. The normal salivary glands were divided into four cases of parotid gland obtained from pleomorphic adenoma from outside the capsule ihrler et. It is assumed that they take part in the expulsion of the saliva, and possibly they support the structures against a distension during secretion. Infiltrating spindle cells with fibrillar eosinophilic cytoplasm tumor appears to arise from myoepithelial cells of ductules at periphery of lesion cells have variable atypia mitotic figures common, but may be less than 410 hpf may have clear cells tohoku j exp med 2003.
Proteins gfap, cd10 and caldesmon were not observed in myoepithelial cells of salivary glands. The mammary myoepithelial cell was named the cinderella of mammary cell biology in light of the earlier focus on the luminal cell. Cutaneous myoepithelial carcinoma with disseminated. The functional unit of the salivary glands is the terminal secretory piece called acini with a roughly spherical or tubular shape. They are preponderantly tumors of the parotid glands with a relatively low mortality but a decided locoregional aggressiveness.
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